Predictors of Progression in Pre-COPD: The 3P Study Rationale and Design - González-Villaescusa C; Tarrasó Castillo J; Martínez-Pitarch D; Riesco Miranda JA; García-Castillo E; Gotera Rivera C; Carrasco Hernández L; Sobradillo Ecenarro P; Signes-Costa J; Naval Sendra E; Callejas González FJ; Yordi León A; et al. (Open Respiratory Archives, 2026)